Tilting induction furnace with leads extending through a trunnion



Dec. 30, 1947. P. c. VOGEL 2,433,495

TILTING INDUCTION FURNACE WITH LEADS EXTENDING THROUGH A TRUNNION Filed'May 31 1945 Patented Dec. 30, 1947 T'ILTIN G INDUCTION FURNAGE" WITHLEADS EXTENDING THROUGH A TRUNNION Paul C. Vogel, Waukesha, Wis,assignor to Allis,- C a mers Manufact r n Co pany Mi wauice, Wis, acorpo a f D la a e Application May 31, 1945, Serial No. 596,837

3 Claims.

i inv nti n rel tes n et e l to PrQ m u in e ectr ea in evi n m piicularly o a ead a an ement for nducti furnaces of the trunnionsupported tilting type.

Induction furnaces and other electric heating devices which are mountedon trunnions are generally provided with flexible leads for connectingthe heating conductor of the device with a suitable source of electriccurrent. When the conductor :or some other element of the devicerequires artificial cooling, flexible insulating hose sections are.generally provided in addition for connecting the cooling circuit witha supply of water or other cooling fluid and with a drain. Theseflexible leads and hose sections are generally attached at some point ofthe device which has a substantial displacement during tilting of thedevice and they must therefore be relatively long. They thus becomecumbersome, interfere with the movement of the device and are in the wayof the Operator.

It is therefore preferable to provide the device with hollow trunnionsof such diameter that the leads and cooling connections of the devicemay be drawn therethrough, whereby the move-v Inent of the flexibleportions of the current and Water connections is considerably reduced,The connections may then be made shorter, with a lesser degree offlexibility, and may be so located as not to interfere with the movementor the device.

The connections maybe completed in Whatever manner is found mostexpedient in each particular instance. For example, the preferred arranement comprises rigid'conductive pip e tions disposed side by sidewithin the trunnion for conducting both the current and the coolingfluid. The leads are connected to fixed terminals through flexibleelectrical connections and are connected with a source of cooling fluidand, if desired, with a drain through sections of insulating flexiblehose.

The pipe sections disposed within the trunnion may also be severallyconnected to the fixed terminals through flexible conductive hose, eachof which serves both for the supply of current and for the supply ofcooling fluid, or through flexible electric conductors encased in theflex;- ible hose serving for the flow of cooling fluid. The flexibleconductors are then fluid cooled and maybe made of smaller crosssectionthan in the absence of artificial cooling means.

'lhe trunnion may also enclose fixed conduca tive pines arranged in sideby sideor coaxial relation and rigidly connected to the fixed currentterminal we as to of oo in uid The nine m y th n. e onnect d to th teminals o the trunn on sup ted device throu h an o the above m nt nedtrees of fl xible. cqnu ction i It is t erei re an biectoi the re e tnventu to. p ovi e an e ectric h at n device of he. tilti ty e withflexible e ect ic urr nt nd cc ling onnect ons which (1.0. not interierwith the t tin movement at the device- Anoth r o ec of the resent. iov niqn is to provide an electric heating device of the tilting ty e in wiqhfiexi l e e tri cur ent an 9 9 me qqnne ti n h ve the east mo ementthan tilt n-ec the device Anothe bje of the Pr sent inven io is iscrevice lec ric tactics device of t e ilt n ype having comm n igi e ec rcu en and in K P-WUQQ and .6 9???" th flex bl l i i l fi wtre it andceding comedians- Ob'ie and advanta es the an h seab c set forth will beapparent from a consideration of the following description when read inconnection with the accompanying drawing, in w c Fig, 1 is a view inside elevation of a trunnion supp r nductio m ltin f na e p ed with apreferred embodiment of current and cooln c nn t ns x endi g h g arunnion thereof; and

Fig. 2 is a view in cross section through line II.,-I I of theembodiment illustrated in Fig. 1.

Reterring more particularly to the drawing by characters of reference,the induction furnace ompr se a c uc le 6 of gra hi e o r m c materialassociated with an inductor coil 1. The ndu tor is a s en i wo nd rom anelongated conduct r of a -.mcta1 of high conduct vity such as copperwith interposition of suitable electric insulation between adjacentturns thereof. The conductor may be of solid cross section if it doesnot require artificial cooling, or may consist of a pipe 8 wound aloneor in parallel with other conductive elements when the inductor is to betraversed by a flow of cooling water or other cooling fluid. Inductor 1is mounted on a pair of j Q trunn ons :0 i any suit b ek own an o rmitilting cruci le 5 w en it is d sired to our mol n me al therefrom o exmple. inductor ma be l i n a ow rame 2 buil o asbestos lum er disposed na asing 13 co pris ng a St u ural frame it an a cove n 10f asb stoslumbe 5- ici 6 s set within inductor land the space thenebetween 3 isfilled with tamped refractory material (not shown).

Trunnions 9, l are fastened to frame M of easing I3 and are supported ina pair of overhanging bearings l1, 18 within which they are free torotate. Downward tilting of casing l3 with respect to bearings ll, I8 islimited by suitable feet [9 provided on frame M. The casing may betilted upward for pouring metal from crucible 6 by means of a hoist 20suitably located with respect thereto and having its cable attached to asuitable lug 2| provided on frame 14.

Trunnion 9 is provided with a plug 22 of suitable insulating materialsuch as fabric reinforced synthetic resin forced into the trunnion. Plug22 is provided with two passages parallel to the axis thereof forreceiving metal pipes 23, 24 integral with pipe 8 or fastened theretoand serving as current leads as well as water flow connections for theinductor. Pipes 23, 24 are associated with stationary piping outletsdisposed adjacent bearing 9. Pipe 23 for example is connected with awater supply pipe 26 through a section of flexible insulating hose 21and a valve 28, and pipe 24 is connected with a drain pipe 29 through asecond section of flexible insulating hose 30. Hose sections 21, 30 aremade of any suitable flexible insulating material such as fabricreinforced rubber and are chosen of such length as to reduce the currentleakage through the water contained therein to the desired extent.

Pipe 23 is provided with a, terminal 3| brazed thereon and movabletherewith and connected to one or more stationary terminals 32 throughone or more flexible conductors 33. Each terminal 32 may consist of acopper bar bolted on a plate of insulating material 34 and connectedwith a suitable current generator (not shown) through the innerconductor 36 of a coaxial insulated cable 37. Pipe 24 is likewiseprovided with a terminal 38 movable therewith connected to stationaryterminals 39 through flexible conductors 49. Terminals 39 are supportedon a plate of insulation 4| and are connected with outer conductors 42of coaxial cables 31. Insulation plates 34, 4| are mounted on a suitableframework 43 of which the outermost elements are assumed to be removedin Fig. 1 to clarify the drawing. During operation of the furnace theentire arrangement of connections of pipes 23, 24 with cables 3'! andoutlets 26, 29 is preferably covered with a hood (not shown) to preventaccidental contact of the operator therewith and to prevent damagethereto by metal spilt during pouring of the charge.

It will be apparent that with the above described arrangement theelectrical and cooling water connections of inductor I are remote fromthe inductor so as not to interfere with the tilting thereof. Theelectrical connections of the inductor with cables 31 are adjacent eachother, whereby the inductance of such connections is maintained at aminimum value. When the charge of crucible S is to be poured, casing I3is lifted by means of hoist 20. Pipes 23, 24 rotate with a minmum radiusand flexible conductors 33, 49 are subjected to a minimum of flexure andmay therefore be made relatively short and compact. While the length ofhose sections 27, 30 cannot be reduced below the value required toprevent excessive current leakage between the conductor terminals, thelife of the hose sections is increased by the absence of excessiveflexure thereof during tilting of the furnace.

Although but one embodiment of the present invention has beenillustrated and described it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

It is claimed and desired to secure by Letters Patent:

1. An electric heating device comprising a. bearing, a hollow trunnionrotatably supported on said bearing, a current conductor rigidly mountedon said hollow trunnion for tilting movement with respect to saidbearing, current leads for said conductor extending through said hollowtrunnion and through said bearing, stationary terminals disposedadjacent said bearing, and flexible conductors connecting said currentleads with said terminals.

2. An electric heating device comprising a bearing, a hollow trunnionrotatably supported on said bearing, a, metallic pipe rigidly mounted onsaid hollow trunnion for tilting movement with respect to said bearing,said pipe defining an electric circuit and forming a passage for theflow of a fluid, electrically conductive pipe sections extending side byside in insulated relation through said hollow trunnion and through saidbearing for supplying electric current and fluid to said pipe,stationary terminals adjacent said bearing, flexible conductorsconnecting said pipe sections with said terminals, a stationary pipingoutlet adjacent said bearings, and a flexible insulating hose sectionconnecting one of said pipe sections with said outlets.

3. An electric heating device comprising a bearing, a hollow trunnionrotatably supported on said bearing, a metallic pipe rigidly mounted onsaid hollow trunnion for limited tilting movement with respect to saidbearing, said pipe defining an electric circuit and forming a passagefor the flow of a fluid, electrically conductive pipe sections extendingthrough said hollow trunnion and through said bearing for supplyingelectric current and fluid to said pipe, electrical insulation disposedwithin said hollow trunnion for supporting said pipe sections side byside in insulated relation with respect to each other and to said hollowtrunnion, stationary terminals disposed side by side in a directiontransverse to the axis of said trunnion adjacent said bearing, bareflexible conductors connecting said pipe sections with said terminals,said terminals being at different heights to prevent short circuitsbetween said conductors during said tilting movement, stationary pipingoutlets adjacent said bearings, and flexible insulating hose sectionconnecting said pipesections with said outlets.

PAUL C. VOGEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,538,365 Willson May 19, 19251,608,801 Masel et al. Nov. 30, 1926 1,723,984 Von Henke Aug. 6, 19291,795.926 Brace Mar. 10, 1931 1,853,101 Von Henke Apr. 12, 19321,862,293 Brace June 7, 1932 2,139,528 Stansel Dec. 6, 1938 2,270,223Galusser Jan. 20, 1942 2,277,223 Goodridge Mar. 24, 1942

